In recent years, a lithium secondary battery as demanded is to have a small size, a light weight, and a high capacity, upon development of portable electronic equipments such as cell phones and notebook-sized personal computers, or practical use of electric vehicles.
Also, the lithium secondary battery is requested to improve various batteries properties along with high-capacity as expanding the apparatus application.
As one way to achieve the improvement of the battery properties in the lithium secondary batteries, it is known to add various additives in the nonaqueous electrolyte liquid of the lithium secondary batteries. For example, Patent Reference 1 discloses that a lithium secondary battery can be improved in view of the charge discharge cycle property and the storage property when using a nonaqueous electrolyte liquid containing a phosphonoacetate compound having a specific structure.
Patent Reference 2 discloses that a lithium secondary battery can be improved in view of the charge discharge cycle properties when using a nonaqueous electrolyte liquid containing 1,3-dioxane and a sulfonate compound.